Iran said progress had been made in recent talks with the US but gaps over nuclear issues and the Strait of Hormuz remained.
Parliamentary speaker Mohammad Bagher Ghalibaf said that even though “progress has been made” in negotiations, they remain “far from final discussion”.
Meanwhile Donald Trump said there had been “very good conversations” with Tehran but he described Iran’s latest closure of the shipping channel as “blackmail”.
Neither side offered any specifics about the state of negotiations on Saturday, days before the ceasefire in the war expires.
It came as two Indian-flagged tankers reported gunfire after Tehran shut the strait on Saturday, which it said came as a result of the continued US blockade of Iranian ports.
Iran’s Revolutionary Guards said the vital waterway, which before the war carried a fifth of the world’s oil shipments, would remain closed until the US lifts its blockade on Iranian vessels.
Trump had earlier said there could be talks this weekend and that the two sides were “very close to making a deal”.
